Sep 11, 2010

Why Do Leaves Change Color In Fall - How Leaves Change Color - The Daily Green

How do leaves change from green to yellow, orange and red? And what's in store for us this year?
By Dan Shapley

Buzz up!
Why do leaves change color?

It's one of those questions – like, why is the sky blue? – that can stump a parent on an otherwise enjoyable fall walk. So let's answer the question.

Most simply, to survive the winter, deciduous trees need to store nutrients in their roots, which means they must absorb the nutrients in their leaves. Changes in color are triggered as the trees absorb essential nutrients. Here's how it works:

Throughout the warm sunny months, trees are lush and green because they're working hard. Tree leaves are green because the abundance of the pigment chlorophyll, which is essential to converting sunlight, water and carbon dioxide into energy-rich sugars. If plants hadn't figured out the trick of photosynthesis, we'd all be out of luck, since the energy humans need to live comes from plants, or the animals that eat plants. Tree leaves are also busy using other essential nutrients, like nitrogen and phosphorus (the same main ingredients in most store-bought fertilizers, or in compost), so these nutrients are abundant in summer foliage.

As summer wanes, changes in tree leaves are triggered by the cooler temperatures, changes in rainfall and weather, and most of all, the shortening of daylight hours. Much of the change happens without our knowing it, as trees begin to absorb essential nutrients and store them in their roots so they are available for the following spring. As the trees absorb the last of the chlorophyll, however, the brilliant colors we associate with autumn begin to appear.

What to Expect for Fall 2010
Or they should, anyway. While leaves will always change color as the amount of sunlight wanes, several weather conditions can affect how brilliant they become. This year, for instance, much of the eastern U.S. has experienced near-record high temperatures and a significant drought, leaving trees stressed enough that many leaves will change straight from green to brown, or drop their leaves early, according to Mark Abrams, a professor of forestry at Pennsylvania State University. A cool, dry September won't help matters.

"I'm starting to notice browning of leaves on the leaf margin and some early leaf fall, and some of the color that's coming out is not very vibrant," he said. "It's pretty hard for me to say that this is going to be a spectacular year. I think because of the very hot summer and particularly the drought we've had, and the unusually dry September we're having ... we'll probably be in the fair-to-good range, but not in the very good-to-excellent range. But that doesn't mean there won't be good colors out there and pockets of very good colors."

But why do leaves change from green to yellow, orange and red under the best conditions?

How Leaves Turn Yellow

Yellow colors that were always present in leaves become unmasked as the chlorophyll is broken down and absorbed. Called carotenoids, these are the yellow pigments that give trees like birch, beech and tulip their bright fall colors. Why are these yellow pigments there in the first place? To protect leaves from the byproducts of photosynthesis, which would otherwise cause damage. (Carotenoids play a similar role in the human body, as it turns out. Beta carotene and lycopene are among the best-known carotenoids, because they are healthy antioxidants in our food.)

How Leaves Turn Red
Red and orange colors, like those that characterize the famous red maples of New England, are made by different pigments, called anthocyanins. For years, scientists were stumped by them: Unlike the ever-present yellows that simply become unmasked when chlorophyll recedes, red pigments are actually created as a tree is going dormant. But why would a tree expend energy to produce a new pigment just as it's hunkering down for the winter? And why do some trees make red pigments, when others don't? Further, the reds of New England are so famous in part because they are unique to the new world. Why are European autumns so predominantly yellow?

In 2001, Bill Hoch, then a grad student at the University of Wisconsin-Madison, found an explanation that has stuck. (He followed up his research with a supporting study in 2003, and he is now an assistant professor at Montana State University's College of Agriculture.)

The new red pigments protect leaves from the sun, giving some species extra time to absorb those essential leaf nutrients, according to Hoch. If chlorophyll is the beach umbrella, anthocyanins are the sunscreen. As chlorophyll exits leaves, anthocyanins are created to buy leaves time to unload nutrients. If you've ever noticed maples turn a deep burgundy before they achieve that crimson red, it's because the burgundy is a mix of outgoing green chlorophyll and incoming red anthocyanins, and the crimson is pure anthocyanin.

"When the leaves are senescing (transferring nutrients from leaves to roots), they're more susceptible to light damage because they're taking themselves apart," Hoch said. "It's like taking parts off your car while you're still trying to drive it."

Anthocyanins, incidentally, are found in many other plants, including foods like eggplant, red cabbage, oranges and many berries. There's some research suggesting that they, too, are important for human health.

But why don't all trees' leaves turn red? It turns out, Hoch said, that yellow trees are those that colonize open land first – so-called pioneer species that are tolerant of direct sunlight. Those that turn red are species that follow in the succession of species that come to dominate a landscape, and they tend to benefit from more protection from the sun. It's not that the red leaves lack the yellow pigment; the red pigment is an addition, and in fall it is so intense that it masks the yellow, just as green does in summer.

"Those pioneer species are less susceptible to light damage," Hoch suggests.

But why are European trees more yellow? It could be that falls there tend to be warmer and cloudier, so there was never any selective advantage for trees to evolve red pigments that would be protective of the sun.

How Weather and Climate Affect Fall Foliage
Because red pigments are created in fall, specific weather conditions can have a big effect on their brilliance. According to the U.S. Forest Service:

A succession of warm, sunny days and cool, crisp but not freezing nights seems to bring about the most spectacular color displays. During these days, lots of sugars are produced in the leaf but the cool nights and the gradual closing of veins going into the leaf prevent these sugars from moving out. These conditions-lots of sugar and lots of light-spur production of the brilliant anthocyanin pigments, which tint reds, purples, and crimson. Because carotenoids are always present in leaves, the yellow and gold colors remain fairly constant from year to year.
The amount of moisture in the soil also affects autumn colors. Like the weather, soil moisture varies greatly from year to year. The countless combinations of these two highly variable factors assure that no two autumns can be exactly alike. A late spring, or a severe summer drought, can delay the onset of fall color by a few weeks. A warm period during fall will also lower the intensity of autumn colors. A warm wet spring, favorable summer weather, and warm sunny fall days with cool nights should produce the most brilliant autumn colors.

Climate change, then, could have a lasting effect on fall foliage, as the cycle of drought and deluge changes, and temperatures warm overall. A longer growing season can keep trees more green later into the fall, when a shock of frost can make them drop leaves before they complete the color-change process. Data from the Mohonk Preserve in New York's Shawangunk Mountains, where naturalists have tracked the weather and the foliage for more than a century, suggest that the peak of fall color is indeed coming later – days or even weeks later, on average.

It's only one consequence of global warming for northern forests. Maples, which fill the forests with crimson, prefer colder climes, and require cold winters to produce adequate sap for syrup. Over time, those trees may grow only farther north, where the climate is more suitable. Insect pests, too, are spreading north as winter freezes grow more mild, and those pests might affect not only fall color, but the value of timber harvests and the health of habitat for wildlife.

Read more:

Sep 10, 2010

Archein: Broken Politics, Bubble Pricing, Environment, and Agriculture

Shed your fears and lose your guilt
Tonight we burn responsibility in the fire
We'll watch the flames grow higher
As I was standing by the edge
I could see the faces of those who led pissing theirselves laughing
Their mad eyes bulged and their flushed faces said,
"The weak get crushed and the strong grow stronger."
In the funeral pyre, we'll watch the flames grow higher
-- Paul Weller

However effective you think "markets" are at pricing, one thing you can say is bubbles completely distort pricing mechanisms to the point of being valueless. When you add into that a corrupt political process using government to further distort costs, you get a system that is completely dysfunctional and incapable of meeting the challenges of the times. Here's two good examples. The first is a piece in the Post about the establishment environmental groups lamenting the fate of climate legislation in DC. Any legislation to increase fossil fuels price was doomed with the financial crisis and resulting economic slowdown, though in return, the slowing economy gave you the greatest reduction in fossil fuel use in 30 years, certainly much greater than any proposed legislation at this point. Much, certainly not all, of the established environmental movement has propagated the notion that the mechanisms, culture, and practices that led us to environmental breakdown are going to be the same ones offering solutions. Let's look at one, the idea that a broken politics, without first being repaired, can get us needed change. The Post has a piece with one of the most ludicrous quotes I've seen in 30 years following politics:
"The oil industry has tremendous reach and control in the United States Senate," said David Di Martino, a spokesman for Clean Energy Works, a coalition of more than 60 groups that includes big names such as the Sierra Club, the Natural Resources Defense Council and the Environmental Defense Fund. "Our mistake was miscalculating . . . how far into the Senate it went."
Miscalculating? Really? The oil industry has power in DC? Don't misunderstand, this kind of political thinking is rampant in environmental circles. Many think they don't need to educate the public and can just pull the levers of a broken system. Try to get money from the big non-profit funders for public education on taxing oil. You can start with Pew founded by Sun Oil, then go to the Rockefeller Foundation, or if both of them don't work try the Ford Foundation. There's few funders who believe in public education, after all its expensive, and well, who wants to deal with the great unwashed. And don't worry, they won't react when the price of energy goes up, Al Gore has told them the world's ending.

Anyway, right now on energy there's two viable things to push, money for renewables and efficiency/conservation.

The environmental movement is simply about looking at the human impact on natural resources and natural systems. Energy of course is fundamental, but even more so is food, you can go without energy a lot longer than without food. Now, there's been a growing number of stories about potash(potassium) appearing in the news, since BHP is attempting to take over one of the world's largest producers. Mined potash is a necessary element to modern agriculture practices. Limited increasingly by area, that is Canada and Russia dwarf all other known reserves, the price of potash, like many other agriculture commodities went through a massive price spike before the financial crisis. Here's an interesting BBC discussion on the entire global agriculture issue(tx zerohedge). Pay attention to Hugh Hendry's quote near the end. He states,
"For thirty-years, the price of agriculture has collapsed, fallen 90% in real terms. So, we haven't invested in this sector. As a society, as a world society we acutely vulnerable to the business of feeding ourselves."
Agriculture prices have been falling for a couple hundred years. Modern agriculture practices developed in the last hundred years are totally tied to fossil fuels, and no doubt, the last three decades precipitous fall is also tied to the preceding great rise in commodity prices caused by the oil crisis of the 1970s. But Mr. Hendry's point is well taken, we haven't invested in agriculture, in large part because our bubble financial system of the past quarter-century has not accurately priced its importance. If you want to bet which of the great environmental threats will be the first to bite us, I'd put money on our completely unsustainable agriculture practices.

The most important point of both these stories is what got us here isn't going to get us out.

BOY! JOE COSTELLO is dead right on this post! ...Monte

Sep 9, 2010

2010 Biochar Symposium - Illinois Sustainable Technology Center - University of Illinois

On September 1st, 2010, ISTC hosted the 2010 Biochar Symposium that featured presentations on biochar production, properties, and use in agricultural environments. Slides and presentations are in order of presentation. LOTS OF GOOD INFORMATION... Monte

Once-Lowly Charcoal Emerges as 'Major Tool' for Curbing Carbon -

September 7, 2010
By PAUL VOOSEN of Greenwire

Charcoal is taking root on the farm.

Simmered out of eucalyptus, charcoal is being hoed into the degraded soils of former forests in western Kenya. Roasted out of chicken manure, it is spurring the growth of malting barley in Australia. And in Iowa, researchers are plowing charcoal into corn rows, hoping to limit the tons of fertilizer that saturate the state's fields each year.

At these farms and more, scientists are probing the limits of how high-grade charcoal, dubbed biochar, can be formed from plant and animal waste to squirrel away the atmosphere's carbon for centuries, or even millennia. Inspired by ancient Amazonian soils, researchers have found that buried charcoal resists bacteria's attempts to break it down. And thanks to its porous geometry, it has a knack for improving land in ways still being revealed.

"Once we get serious about climate change, this information is available now," said James Amonette, an environmental geochemist at the Energy Department's Pacific Northwest National Laboratory. "[Biochar] is one of the major tools we can use to fight climate change, if we decide to do so."

Charcoal's status may be comparable to the start of the world's head-over-heels embrace of synthetic fertilizer a century ago, scientists say. As piling evidence shows, converting organic matter -- be it corn scraps, human sewage or chicken litter -- to charcoal can, in effect, increase the carbon cycle's latency by hundreds of years, buying humanity just a bit more time to solve its fossil fuel fix.

While it has roots in decades-old research, the biochar movement took life only recently, as soil scientists realized the scope of charcoal's climate implications. The field, rich in unanswered questions, has exploded in the past five years, leading several hundred scientists to gather this month in Brazil for the world's third annual biochar conference.

"Biochar is certainly not a fringe science anymore," said Lukas van Zweiten, an Australian researcher running one of the world's largest biochar field trials. "[It's] a big change from five years ago, when we were still trying to convince the scientific community of its worth."

Even Washington is digging into biochar. Last year, Senate Majority Leader Harry Reid (D-Nev.) introduced a bill supporting biochar research, and provisions tucked into the stalled climate measure sponsored by Sens. John Kerry (D-Mass.) and Joe Lieberman (I-Conn.) direct the Agriculture Department to provide grants to up to 60 research projects. It is funding that is sorely needed -- currently, there is not enough biochar being produced to meet even scientific demand.

In Brazil, scientists will complain about lack of funding, of course, but they will also detail recent progress made in understanding why biochar can be so beneficial for degraded soils. They will discuss how variable biochar can be, depending on its source. (Forest and chicken waste, it turns out, are not created equal.) And they will tamp down some of the rapturous rhetoric that can accompany charcoal's agricultural potential.

"Biochar is not a fix for all problems," be it soil quality or climate change, said Johannes Lehmann, a scientist at Cornell University and perhaps the leading biochar researcher. It will only improve soil that can be improved, he said. "Whether it's a viable global strategy? Nobody can say at this point."

Biochar may not sequester all of society's excess carbon, but it can play a tangible role in limiting emissions. Projections recently released by Amonette have found that biochar could trap the equivalent of 12 percent of the world's greenhouse gas emissions a year, in sustainable scenarios. Such a plunge, however, would carry steep economic costs and would likely only be spurred by putting a price on CO2 emissions.

In effect, these researchers believe that biochar will allow society to generate energy from plant waste and nonfood crops -- a combustible oil is the major byproduct of charcoal production -- while also ticking down CO2 emissions. Plants naturally absorb atmospheric CO2 to build themselves up and by delaying the escape of that carbon once crops die a thumb is placed on the carbon-cycle scale, mitigating emissions.

Unlike the geological CO2 sequestration proposed for coal-fired power plants, biochar can operate on small scales. It can be produced in massive factories but also in small stoves tagged for distribution in the world's poorest regions, which often also have impoverished soil, an option that has drawn interest from the Bill & Melinda Gates Foundation. Such stoves, though they might not produce ideal charcoal, possess a rare trait in the development world: poverty relief that also reduces CO2 emissions.

For many scientists, biochar is about much more than climate change. It is a chance to rewire agriculture. For too long, farmers have neglected soil health, instead dousing their fields with escalating amounts of synthetic fertilizer, heavy in nutrients, to boost plant growth, said David Laird, a soil scientist at Iowa State University.

"Soil quality has not been the focus of a lot of research or industry over the years," Laird said, with attention instead locked on fertilizer and irrigation. "Char is a paradigm shift. It puts the emphasis on building the soil resource base itself. That's the opportunity."

'Many different chars'

It is appropriate that this month's biochar conference is meeting just south of the Amazon.

It was there, decades ago, scientists found an unusually productive dark soil called terra preta that was rich in charcoal, among other ingredients. Seeds planted in the soil grew with unusual vigor and to surprising heights. The charcoal was ancient, its radiocarbon dating stretching back thousands of years. It had lingered, resisting degradation, for all that time.

Many believe that lost Amazonian cultures intentionally created the charcoal, though that is far from a settled fact, said Lehmann, who lived and worked in the central Amazon in the late 1990s. At first, Lehmann was not working directly on terra preta, but the draw was unavoidable. "You can't help but be interested in it," he said. The soil was so rich in nutrients and had just the right acidic balance.

"The sheer fact there were soils that were undoubtedly generated thousands of years ago and maintained a higher carbon content ... that was really kind of astounding in that environment," he said.

Whether the charcoal was created artificially or naturally -- some Australian soils are also rich in charcoal, the impromptu briquets caused by the continent's legendary wildfires -- it formed by a technique known as pyrolysis. Believed to be one of mankind's oldest energy technologies, pyrolysis is a simple process: Carbon-rich organic compounds are baked under moderate temperatures, around 500 degrees Celsius, in nearly oxygen-free conditions.

The world is a different place without oxygen, and that holds true for pyrolysis. With oxygen, organic material -- called, in shorthand, biomass -- bursts into flame, releasing nearly all of its energy and carbon into the atmosphere, with piles of ash left behind. Without oxygen, the biomass resists ignition, instead separating into flammable oil and charcoal, a porous solid composed of disordered, stable stacks of ring-like carbon molecules, along with ash.

These carbon rings helped keep the terra preta stable through the centuries, resisting the bacteria that normally break down other supplements, like compost or manure, as it is slowly driven deeper into the soil by earthworms. Manure falls apart quickly, especially in tropical heat, while charcoal can last up to 100 times longer in the soil, recent research has shown -- hundreds of years, or even thousands.

Biochar's stability tends to vary with the climate, just like normal biomass. If a leaf falls in Nigeria, for example, it will degrade in a week, but if the same leaf falls in the depths of Siberia, it will last much longer. The point is that against normal biomass, biochar lasts many multiples longer. At least, the right kind of biochar, Lehmann said.

"We need to recognize that there are many different chars that have many different effects on soil," he said. The process for creating the charcoal varies, as do feedstocks. "A biochar from poultry litter is less stable than one from oak wood," Lehmann said. "But poultry is also less stable than oak wood."

According to Amonette, biochar's stability provides half of its greenhouse gas benefit; another third derives from replaced fossil fuel energy, and one-fifth to avoided emissions of methane and nitrous oxide, both powerful greenhouse gases. (The degree that biochar limits nitrous oxide emissions remains a matter of debate.) For nearly every farming region, it will be better to produce biochar for energy, rather than simply burning waste, Amonette's study found, except for areas with already fertile soil that depend on coal-fired power plants.

Like biofuels, biochar has the potential, if widely used, to see forests sacrificed to farming, or food crops used instead for fuel. Well aware of these problems, Amonette's projections relied only on the use of agricultural and human waste, along with dedicated energy crops that would only be grown on abandoned, degraded soil, he said. Estimates for biochar's offset potential could have run higher, but not without untold indirect consequences.

There are other possible indirect consequences, Amonette added. Darkening soil with finely ground charcoal could cause more sunlight to be absorbed. And should too much charcoal escape into the air, it could become the equivalent of black carbon, blowing into arctic regions and glaciers, its darkness causing increased heat absorption. Watering down charcoal before use will limit those concerns, though, Iowa's Laird said.

For some crops, biochar is a no-brainer, particularly rice, Amonette said. Water lies stagnant in paddies for weeks or months at a time. Bacteria feed off the rice waste and suck oxygen out of the water, creating space, once the oxygen is gone, for microbes that emit methane. ("Take any soil, put it in a beaker, and in a few weeks you'd be producing methane," Amonette said.) Steps to eliminate such methane emissions with biochar, including production from manure and yard waste, make immediate sense, he said.

In other environments, biochar could prove an ineffective carbon sink, scientists warned. Seeding forests does not seem particularly promising, especially in colder climates. And there needs to be more study of the overall influence charcoal has on soil, Iowa's Laird added. Does it bump the growth of carbon-chewing microbes? Does it encourage more carbon to settle?

"We actually have data that say both," Laird said.

The Swedish biologist David Wardle has been one of the most prominent researchers calling for calm in the charcoal rush. He conducted a 10-year study of charcoal's interaction with forest tundra and found that the charcoal accelerated the loss of carbon. (Wardle's methodology may have been flawed, however, as it did not account for new charcoal-caused carbon deposits, Lehmann said.) It is one data set for one region, but the upshot is that a more holistic accounting needs to take place, Wardle said.

"A more realistic vision is a more nuanced vision," he said. "If you have [charcoal] in the soil, there will be long-term consequences on microbial activity. It's not as simplistic as it initially seems."

Improving soil

While biochar's carbon storage grabs headlines, what gets soil scientists exercised is its potential to improve soil in the United States and, especially, in the tropics, where so many currently suffer from food insecurity. For too long, farmers have focused on improving yield with fertilizers derived from natural gas, Amonette said. The soil itself has been neglected.

Cornell's Lehmann has been at the forefront of testing how African soils could take to charcoal, running trials in western Kenya's highlands for six years. Over the past century, the highland forests have been slowly razed for agriculture, resulting in a gradient of soil richness, from the lush dirt of recently deforested land to plots that have been farmed, year after year, for a century -- a perfect experimental site.

In these trials, Lehmann found that, after several years, the amount of corn grown per plot doubled in older soils supplemented with biochar. The yield gains were not unprecedented: By spreading dead sunflowers across the soil, scientists made similar improvements. But unlike the mulch, which will erode unless reapplied, the biochar's benefits will linger, Lehmann said.

Similar studies have paralleled Lehmann's work across multiple continents -- China is building a large biochar research cohort -- over the past five years, to varying results. In the United States, biochar has potential for the southeast United States, where soil is nearly as poor as the tropics. Fruit and vegetables grown in California's Central Valley, too, are promising targets, Amonette said.

Such empirical trials are necessary, the grist of science. But as they have gone forward, soil scientists have grappled with a more fundamental question: Why does dumping a poor man's version of graphite, which holds little of the mineral nutrients found in fertilizer, send corn stalks soaring? The answers, provisional and halting, are beginning to come, Lehmann said.

"We're starting to be able to put our finger on the process by which biochar improves soils, or in some cases doesn't," he said. "Up to now a lot of that research was empirical."

There is no one reason biochar improves soil, but many, researchers have found. Biochar is porous at the microscopic level, its nooks and crannies creating a massive surface area to catch bacteria and nutrients like nitrogen. Its structure seems to retain water, and depending on the feedstock, biochar can balance soil acidity. Most intriguingly, charcoal carries a negative electrical charge through its structure, attracting positively charged nutrients like calcium, potassium and magnesium that might otherwise flush away.

These are all useful mechanisms, but not useful everywhere, cautioned Australian researcher van Zweiten.

"We have examples where biochar does very little, at least in the short term, in soil, while other examples show quite stunning improvements in soil fertility and productivity," van Zweiten said. Farmers should not get ahead of themselves in expectations, he said, "that biochar is always going to do good things in the soil, because I know for a fact this is not the case."

Some of van Zweiten's earliest field trials, on subtropical pasture in Australia, saw little in the way of additional growth when one biochar variety was added, he said. Another trial, though, begun three years ago, has had large yield gains for a mix of crops, such as malting barley; the site's control plots, fed only fertilizer, are failing.

Few places have better farming soil than Iowa, where Laird tests biochar on row after row of corn. Given these conditions, biochar will only add a slight yield improvement, if any, he said. Laird's hope, instead, is that charcoal will improve soil's nutrient efficiency, dropping the vast amount of synthetic fertilizer dumped on cash crops each year, much of which then leaches into the watershed to cause seasonal "dead zones" in the Gulf of Mexico.

The nutrient efficiency questions are far from answered. "It's going to take time to put all the pieces together and be able to come up with definite answers," Laird said. But while it is not yet proven, he said, "I think we need to move ahead with testing of this at a significant scale."

Revving up production

Pushing biochar use out to a scale large enough to spur some corporate investment is one of the goals of the International Biochar Initiative (IBI), a nonprofit lobbying group founded several years ago.

The initiative, led by Debbie Reed, a former legislative director under President Clinton at the White House's Council on Environmental Quality, has been behind language supporting biochar research in the Senate's recent climate bill, as well as the 2008 farm bill.

According to Lehmann, who serves as IBI's chairman, getting biochar production up and running should be a priority for the agricultural community. Often, Lehmann gets requests from farmers interested in testing charcoal, and he has to turn them away. He barely has enough for his own trial fields, a situation shared by Iowa's Laird.

"There are not enough biochar plants around that you can generate the biochar to fulfill even the scientific community's interest," Lehmann said. "We need to catch up, dramatically. There's a little bit of urgency to meet that demand."

Increased production should be accompanied by a classification system that can easily explain different biochar varieties, an effort being led by IBI. Currently, "there are lots of people who say they are creating biochar," Reed said. But many of these products are high in ash and would never qualify as proper biochar, she said.

A grading system would also need to take account of soil differences, Laird added. For example, he said, "'Grade A' char is fantastic for acidic soils in the southeastern United States. But you would not want to put it in the Western corn belt."

All sorts of best practices need to be established, Lehmann said. The government should be concerned that some biochar feedstocks could carry heavy metal contaminants or dioxin, though regulations governing manure and composts could easily be adapted for charcoal, he said. The pyrolysis process can also eliminate many problems, Australia's van Zweiten added.

"Like these other products, what you put in is what you get out," van Zweiten said. "The key advantage over these products is that organic contaminants ... can usually be dealt with effectively during pyrolysis."

Most scientists believe that the waste-management industry will be the first to stimulate biochar production, but even then there is doubt that investment will come without a price on CO2 emissions. Van Zweiten, however, believes biochar can be profitable even without a carbon cap, at least in soils that respond to charcoal.

In the end, it could be the powerful farm lobby that will ultimately push biochar forward. Farmers have long desired a way into the carbon markets that would be created by potential climate legislation, if it ever moves forward. And biochar could provide the greatest certainty that their biological carbon sinks cause true emission offsets, though only time will tell.

"Biochar becomes increasingly viable once we make a societal decision to deal with climate change," Amonette said. "Until we do that, it will remain a niche."


Sep 7, 2010

Michael Moore on His Life, His Films and His Activism


Listen/Watch September 06, 2010

Choose a file format below:
Very worthwhile watching! He is very funny! You will laugh! ... Some love him!... Some hate him!... He is always ahead of his time and is almost always right!... I love his courage and his sacrifice!... Monte

Beyond the Hype (Biochar) - Biomass Magazine

Overview of the sustainable biochar concept.Beyond the Hype (Biochar)
By Anna Austin

The hype surrounding biochar as a climate change mitigation tool, soil amendment or power source is mesmerizing with promises of miraculous results. Too much talk and not much action, however, has raised doubts about its potential.

Market development has been inching along for years, but with no price on carbon there are no incentives for regions with decent-quality soil to use biochar as a soil amendment or for carbon sequestration. In addition, the capital costs of building production facilities are high and often unattainable.

However, new research is confirming biochar's climate mitigation potential and discovering additional applications. A recently published research paper authored by some of the world’s leading soil scientists shows that biochar has the potential to mitigate up to one-tenth of current greenhouse gas (GHG) emissions. The study takes into account the utilization of biomass resources untapped today and does not propose converting any additional acreage into cropland.

Study co-author James Amonette says he hopes the paper, "Sustainable Biochar to Mitigate Global Climate Change," will influence members of the scientific community and policy makers to accept biochar as a valid climate change mitigation technique. He doesn’t view biochar is the final or only solution, but believes it is one of several key players.

Building a Solid Case

Amonette, a soil scientist at the U.S. DOE’s Pacific Northwest National Laboratory, says for the past several years he has wanted to produce a solid biochar study and finally got started in 2009 after discussions with study co-author Dominic Woolf of Swansea University in Wales. “We are extremely concerned about climate change and ways to mitigate it, and independently arrived at the conclusion that nobody has done a real thorough study on biochar,” he says.

Amonette and fellow researchers calculated that when taking into consideration all biomass resources presently available, biochar has the potential to sequester 1 to 2 gigatons of carbon per year. “We really need about 15 gigatons per year carbon equivalent, so it’s not the panacea,” he says. “At the same time, it’s a significant player, and the goal of this paper is to make a solid case for biochar that the scientific community can understand and accept because a lot of people are really turned off by the hype.”

The most difficult component of the study, according to Amonette, was determining the availability of a sustainable supply of biomass. “We relied heavily on some work done earlier,” he says. “Basically, we had to sort out how much biomass is already being used for various purposes, how much is being left and how much we can take off the soil/land without causing soil erosion.”

In rice paddies, Amonette says, it was relatively simple to determine soil impacts because the land is flat so there’s no concern about erosion. “You can pretty much take all the residue from a rice paddy and convert it to biochar at some point,” he says. “You may want to use the rice straw for animal bedding, but rice husks could be used at any time because there is no good use for them.”

Wheat and corn are grown on land that slopes, and removing too much residue can cause major soil erosion problems. “You have to leave a certain amount on the surface or you’ll be exacerbating that part of the problem,” Amonette points out. “So we had to, depending on the crop, look at soil fertility classifications around the world—there are seven different classes of soil that we used—and a major component of that is how steep are the slopes and how rocky is the soil. We looked at those things to determine how much residue could be taken off.”

Following their sustainable biomass assessment, the researchers compared the tradeoffs of using the available material as a soil additive such as biochar as opposed to using it to generate bioenergy. Initially, they found that, on average, biochar is 20 percent more effective than bioenergy at mitigating climate change, Amonette says. “We then did a second analysis that proved, depending on the fertility of the soil to which the biochar was applied and on the power source or type of fossil energy being offset, in some instances, bioenergy was a better climate mitigation option.”

What is the better use for the biomass varies greatly from one scenario to the next. “Instead of competing though, they can work together,” Amonette says. “Bioenergy is still a very good way to go, but it’s not going to solve the problem by itself. It has the same limitations that biochar does.”

Carbon Prices and Soil

From Amonette’s perspective, the bioenergy route will continue to be chosen over climate mitigation because there is still no value for carbon. “Looking at the Midwest, it has fertile soils but uses a lot of coal, so that would be where you want to produce bioenergy,” he says. “Biochar doesn’t make sense there, because if you add it to the soil you won’t get a response. In the Southeast or the tropics where you’ve got these poor soils, it’s a whole different matter and biochar makes a lot of sense.”

Biochar probably won’t be used for climate mitigation until it becomes economical to do so, Amonette says. “That’s when carbon storage becomes valuable,” he adds.

Johannes Lehmann, associate professor of soil fertility management and soil biogeochemistry at Cornell University, echoes Amonette’s views on carbon pricing prompting the use of biochar to combat climate change. “We don’t really know what the value of biochar is right now,” he says. “We’re just beginning to be able to put together accurate data on that—carbon prices that would make this economically feasible.”

Lehmann, who contributed to Amonette’s research paper, says that production efforts are currently focused on producing bioenergy from pyrolysis where biochar is simply a byproduct, but most have not yet been successful. This situation is common in bioenergy production, he says. “For example, methane generation is fairly successful in Europe, especially in Germany, where you have guaranteed feed-in rates. In the U.S. it’s not very successful. Situations like that may change as energy prices change, and maybe there will be a carbon price at some point and then everything will change. At the moment, however, it seems in many countries, including the U.S., making ends meet by just producing bioenergy is difficult.”

As far as using biochar as a soil improver, Lehmann says that depends on the location and the crop being produced, which is no different than when considering the use of nitrogen fertilizer. “You put different amounts of it on different crops, in different soils and at different times of the year,” he says. “You really can’t say what the value of nitrogen is across the world, and you can’t say what the value of biochar is across the world. Biochar has shown tremendous yield increases in some situations with some crops and soils, but for others the soils are good enough and the biochar doesn’t improve it.”

At the moment, the perception is that biochar can miraculously enhance soil quality and magically improve crop growth, but that is not always the case, Lehmann says. “It is more effective than compost,” he says. “It has a greater surface area, has a greater ability to hold onto nutrients to make them available to the plants, and it is also one to two magnitudes more stable than compost.”

Those characteristics alone make it more attractive than compost, he adds, if the objective is to improve the soil and enhance its nutrient holding capacity. “You need to know what you’re managing your soils for.”

That is the purpose of a research project conducted by the USDA-Agricultural Research Service in Prosser, Wash.,—to further enhance the value of biochar by sequestering nutrients from dairy manure lagoons. Hal Collins, soil scientist/microbiologist and project leader, says the concept was successfully proved, but the one hurdle he has encountered is finding someone to provide a system to produce mass amounts of biochar.

Adding More Value

Using waste material from a nearby dairy with an anaerobic digester, Collins and his team were originally taking the liquid waste material from lagoons and applying it to soils as a nutrient source, as well as applying the fiber material as compost. The problem with using the liquid dairy manure is mainly the cost of transporting it to the field. “It’s such a huge cost to move liquid from one location to the other, so if you can concentrate nutrients much like the fertilizer industry does, you’re moving much less bulk,” Collins says.

In the past, Collins has worked on applying biochar to soils, and discovered its cost to be high as well. “Entrepreneurs want about $200 per ton of biochar, and our studies don’t show much of an improvement in soil until about 10 tons of biochar is applied on an acre, so that’s about $2,000 an acre,” Collins says. “Our thought was we have this source of material, and also a problem with the high amount of nutrients in a small location like a dairy. We could take this material, pelletize it, pyrolyze it and obtain energy from that, and then put the biochar back into the lagoon with a filtering system in order to sequester the nutrients.”

About 40 grams of biochar per liter of effluent was added to the 378-liter test lagoon and was then left for 15 days. Test results demonstrated the removal of 68 percent of the phosphorous and 14 percent of the nitrogen from the effluent. Mineralization experiments showed that 85 pounds of phosphorous per acre would be available to crops after the addition of 5 tons of enriched biochar per acre.

According to Collins, dairies in Washington could produce 230,000 tons of nutrient-enriched biochar a year from manure, reducing leaching and runoff. He envisions the entire process occurring at a dairy or hog farm, where they would also be able to generate their own power via the pyrolysis process.

So what’s next? Collins is still trying to find a pyrolysis unit that is able to make enough material to allow widespread field application. “We have had no luck,” he says. “There are a lot of promises to build these units, but I haven’t seen any. I don’t fault them for not getting up and running, though, as it is all about money and the investors just aren’t there.”

Collins says he built his own pyrolysis unit to make biochar, but what he really wants to do test is the quality of the biochar that the future industry will produce, rather than biochar produced under highly controlled conditions. “I understand there should be some companies in Oregon bringing units on line fairly soon, some of whom I’ve been speaking with,” he says. One of those belongs to Halfway, Ore.-based Biochar Products Inc., which is working with Advanced Biorefinery Inc. in Canada to bring a mobile, 1-ton per day fast pyrolysis unit on line. Owner Eric Twombly says the machine has already been demonstrated in the forest, and after fixing a few engineering problems, a multi-stop demo trip in California is planned for next spring.

Twombly says a lot of people have claimed that they are able to build a biochar plant, but few have—partially because of a lack of capital, but also because many systems just aren’t viable. “As much noise as there is about it, the problem is that it isn’t as simple as it seems,” he says. “It’s easy to take a couple barrels with wood in it and make biochar out of it. Almost all slow pyrolysis systems require a batch process. When that batch process gets bigger, it needs a longer residence time. Once you scale it up, you can’t produce very much, and that’s the real limit.”

Although researchers are currently willing to pay $1,000 to $2,000 per ton for biochar, in the long term it will probably be worth about $100 per ton, Twombly says. “If you’re making 2 or 3 tons a day, that doesn’t pay the bills, especially for biochar-only machines that don’t belong to a farmer or those that aren’t integrated with some other project where there’s a need to get rid of waste.”

Looking Ahead

While the price of carbon, the absolute impact of using biochar as a climate mitigation tool, and the production, transportation and storage economics of biochar remain uncertain, Lehmann says there will be tradeoffs that will even out. “When applying it to soil, even if only 1 teragram (1 million metric tons) or 50 teragrams of carbon is offset globally with biochar, we will have improved soil quality and happy farmers,” he says. “It still withdraws some carbon from the atmosphere, and that is a good way to go because it is a no lose.”

Twenty-five years from now, the idea of what is sustainable may change, Amonette adds. “The global crisis may have deepened, and we could be looking at total disaster verses a small disaster, in which case there may have to be some tradeoffs that people make.”

Anna Austin is a Biomass Magazine associate editor. Reach her or (701) 738-4968.